1. Field of the Invention
The present invention relates to a technique for supporting driving at an intersection, and especially relates to a technique which attracts drivers' attention by an alarm when a vehicle intends to proceed into an intersection and cross the opposite lane.
2. Description of the Related Art
Patent document 1 discloses a device for supporting safe driving at an intersection. When a vehicle is waiting at an intersection to turn right, a roadside machine sends, to the device, a type and a form of the intersection, existence of an oncoming vehicle, a type of a vehicle on an opposite lane, a vehicle speed, an inter-vehicle distance to a preceding vehicle, an image of the intersection, existence of a pedestrian, and a lane condition after the vehicle turns right (information on a driving state of an oncoming vehicle, and information reflecting a traffic condition), and the device determines right turn timing based on the data and outputs the timing to a driver.
[patent document 1] JP2009-31968A
In a driving support control in the case of turning right on a road kept left, drivers' attention is attracted by an alarm such as screen display and sound output by using detection information by an object detection sensor in a roadside machine to avoid a risk of a collision with an object such as an oncoming vehicle and a pedestrian. If a vehicle detection sensor for detecting an oncoming vehicle and a human detection sensor for detecting a pedestrian on a pedestrian crossing on the right side are disposed as an object detection sensor, an oncoming vehicle and a pedestrian at risk for a collision can be detected as a detection target when a vehicle turns right. However, if only the vehicle detection sensor is disposed, a pedestrian cannot be detected. Further, if only the human detection sensor is disposed, an oncoming vehicle cannot be detected. As described above, a detection target of a roadside machine is varied according to a type of the disposed object detection sensor.
When a vehicle turns right at an intersection on a road kept left, the vehicle crosses an opposite lane and passes through a pedestrian crossing on the right side. Therefore, when the vehicle is waiting at the intersection to turn right, first a driver pays attention to an oncoming vehicle on the opposite lane, and there is no oncoming vehicle, the driver pays attention to a pedestrian crossing on the right side. In this manner, a driver confirms safety by confirming that there is no oncoming vehicle and then confirming that a pedestrian is not working on a pedestrian crossing on the right side.
If an alarm is not output when a vehicle is waiting at an intersection to turn right, a driver recognizes that the vehicle can safely turn right, and then the driver visually confirms safety. However, at an intersection where an alarm has been output in the past when a vehicle has been waiting to turn right, if an alarm is not output this time when the vehicle is waiting to turn right, a driver easily recognizes that the vehicle can turn right and may not sufficiently confirm safety.
If a vehicle detection sensor and a human detection sensor are disposed at an intersection, a driver can detect an oncoming vehicle and a pedestrian to watch out for when turning right at the intersection. Therefore, a driving support control can be appropriately performed when a vehicle turns right. However, if only the vehicle detection sensor is installed, there is a problem that a pedestrian cannot be detected. Further, if only the human detection sensor is installed, there is a problem that an oncoming vehicle cannot be detected. Therefore, the inventor of the present invention considers a method for the driving support control in each case.